Self-formation of well-arranged nanometric scale templates on solid surfaces has been extensively studied in recent years (C. Becker et al., Topics in Current Chemistry 287, 45 (2009)). This is mainly because these surfaces provide the advantage of forming well-defined and highly ordered nanostructures in scale lengths that are not feasible when conventional lithography techniques are used. Stepped surfaces with high uniformity and regularity can be obtained by the miscut of single crystals in a metal (S. Rousset et al., Materials Science and Engineering: B 96, 169 (2002)) or semiconductor (T. Christian, Physics Reports 365, 335 (2002)) via ion bombardment at a small angle to a plane of low surface energy and high symmetry. This produces high-index surfaces, which usually possess high surface energies. To lower the surface energy, the high-index surface is subjected to surface faceting in a periodic pattern upon annealing at high temperatures, thus revealing periodic single-atom high terraces of low-index planes. This process yields different periodicities, which can be obtained with terrace lengths ranging from several to hundreds of nanometers, and which are precisely controlled by the miscut angle. These faceted surfaces are widely referred to in the literature as “vicinal surfaces” and are extensively used in many different applications.
Vicinal surfaces of face-centered cubic (FCC) metals have found considerable use in microelectronic applications (C. Didiot et al., Nat Nanotech 2, 617 (2007)). These variant 2D lateral structures, composed of terraces and step edges, have characteristic position-dependent electronic states, and hence are known to form unique surface electronic wave functions (A. Mugarza et al., Physical Review Letters 87, (2001); J. E. Ortega et al., Physical Review B 65, 165413 (2002)). Atomic sites on a step edge have low coordination numbers and are thus far more reactive than atomic positions within a terrace. These surfaces are therefore ideal for use as prominent catalytic agents (W. L. Yim et al., The Journal of Physical Chemistry C 111, 445 (2006); Z. P. Liu et al., Journal of the American Chemical Society 124, 14770 (2002); F. Tao et al., Science 327, 850 (2010); M. S. Altman, Science 327, 789 (2010)), as nanostructured templates for directing nanowire arrays (U.S. Pat. No. 7,569,470; D. Tsivion et al., Science 333, 1003 (2011)), for patterning quantum dots and magnetic domains (U.S. Patent Application No. 2006/0202292; C. Didiot et al., Nat Nano 2, 617 (2007); S. Shiraki et al., Applied Surface Science 237, 284 (2004); J. V. Barth et al., Nature 437, 671 (2005); A. Tejeda et al., Europhysics Letters 71, 117 (2005)), and for assembling organic molecules such as self-assembled monolayers (N. Battaglini et al., Langmuir 24, 2042 (2008)), graphene (M. Treier et al., Surf Sci 602, L84 (2008)) and C60 (J. Kröger et al., J. Phys.: Condens. Matter 18, S51 (2006)).
A drawback of the hitherto known process of forming vicinal surfaces, which prevents it from leading to any significant technological breakthrough, is the expensive, inflexible and limited use of single crystals as well as the need to perform these procedures under Ultra-High Vacuum (UHV) conditions. Novel methods for preparing vicinal-nanosteps that avoid the drawbacks of the prior art are highly desirable. It was not previously known that it is possible to form vicinal surfaces of single atom dimensions on a polycrystalline material.